Spiropiperidinenaphthoxazine compound

ABSTRACT

A spiropiperidine-naphthoxazine compound represented by the following general formula (I) is valuable as a photochromic compound: ##STR1## wherein (a) R 1  represents a C1-C18 alkyl group, C7-C15 aralkyl group which may be substituted, a C1-C10 alkenyl group or a C6-C15 aryl group which may be substituted, (b) R 2  through R 9  represent a group R 1  defined above, a hydrogen atom, or a C5-C10 alicyclic ring or a norbonyl or adamantyl group, which is bonded between groups present on one skeleton carbon atom or between groups on adjacent skeleton carbon atoms (at the ortho-position), (c) R.sub. 10 represents a C1-C18 alkyl group, a C7-C15 aralkyl group which may be substituted or a C1-C10 alkenyl group, and (d) R 11  through R 16  represent a hydrogen atom, a C1-C9 alkyl group, a C1-C5 alkoxyl group, a halogen atom, a nitro group or a cyano group.

DESCRIPTION

1. Technical Field

The present invention relates to a novel spiropiperidine-naphthoxazinecompound. More particularly, it relates to aspiropiperidine-naphthoxazine compound having photochromiccharacteristics giving an excellent repeatability.

2. Background Art

By photochromism is meant a reversible phenomenon wherein the color of acompound is changed under irradiation with light containing ultravioletrays, such as sunlight or the light of a mercury lamp, and when thecompound is placed in the dark place and irradiation is stopped, theoriginal color is restored. A compound exhibiting this phenomenon iscalled "a photochromic compound".

Many photochromic compounds have been heretofore synthesized but veryfew compounds are practically used on an industrial scale. This isbecause, when photochromic compounds are used several times repeatedly,the photochromic compounds are deteriorated and they fail to show aphotochromism or the color quality is degraded. Because of this defect,although many photochromic compounds and their applications have beenproposed in patent publications and the other literatures, only alimited number of compounds are practically used.

Recently, a photochromic compound having a relatively good adaptabilityto repeated use has been proposed, for example, by H. G. Heller et al inJ. Chem. Soc. Perkin Trans. I, 1981, page 202. However, thisphotochromic compound still has an insufficient adaptability to repeateduse.

DISCLOSURE OF THE INVENTION

We carried out research with a view to overcoming the above-mentionedproblems of the conventional technique and improving the adaptability torepeated use of a photochromic compound. As the result, we found chromiccompounds having an excellent adaptability to repeated used and have nowcompleted the present invention based on this finding.

More specifically, in accordance with the present invention, there isprovided a spiropiperidine-naphthoxazine compound represented by thefollowing general formula (I): ##STR2## wherein (a) R₁ represents alinear or branched alkyl group having 1 to 18 carbon atoms, an aralkylgroup having 7 to 15 carbon atoms, which may be substituted, an alkenylgroup having 1 to 10 carbon atoms or an aryl group having 6 to 15 carbonatoms, which may be substituted, (b) R₂, R₃, R₄, R₅, R₆, R₇, R₈, and R₉represent independently a group R₁ defined above, a hydrogen atom or analicyclic ring having 5 to 10 carbon atoms or a norbonyl or adamantylgroup, which is bonded between groups present on one skeleton carbonatom or between groups present on adjacent skeleton carbon atoms (at theortho-position), (c) R₁₀ represents a hydrogen atom, a linear orbranched alkyl group having 1 to 18 carbon atoms, an aralkyl grouphaving 7 to 15 carbon atoms, which may be substituted, or an alkenylgroup having 1 to 10 carbon atoms, and (d) R₁₁, R₁₂, R₁₃, R₁₄, R₁₅, andR₁₆ represent independently a hydrogen atom, a linear or branched alkylgroup having 1 to 9 carbon atoms, an alkoxyl group having 1 to 5 carbonatoms, a halogen atom, a nitro group or a cyano group.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an NMR spectrum of the compound prepared in Example 1;

FIG. 2 shows an IR spectrum of this compound;

FIG. 3 shows a visible ray absorption spectrum of this compound; and,

FIG. 4 is a diagram illustrating the adaptability of the compound (a)prepared in Example 1 to repeated use, in contrast to that of thecompounds (b) and (c) obtained in Comparative Examples 1 and 2.

BEST MODE FOR CARRYING OUT THE INVENTION

The spiropiperidine-naphthoxazine compound of the present invention is anovel compound not disclosed in any literature reference. Preferredexamples are compounds of the above-mentioned general formula (I) inwhich (a) R₁ represents a linear or branched alkyl group having 1 to 4carbon atoms, (b) R₂, R₃, R₄, R₅, R₆, and R₇ represent independently ahydrogen atom, a methyl group or an ethyl group, (c) R₈ and R₉ representindependently a methyl group or an ethyl group, (d) R₁₀ represents ahydrogen atom or a linear or branched alkyl group having 1 to 5 carbonatoms, and (e) R₁₁ through R₁₆ represent independently a hydrogen atom,a halogen atom or an alkoxyl group having 1 to 5 carbon atoms. Asspecific preferred examples of the spiropiperidine-naphthoxazinecompound, there can be mentioned (i)1,3,3-trimethylspiropiperidine-2,3'-[3H]-naphth-[2,1-b]-1,4-oxazine,(ii) 1-ethyl-3,3-dimethylspiropiperidine-2,3'-[3H]-naphth[2,1-b]-1,4-oxazine, (iii)1-n-propyl-3,3-dimethylspiropiperidine-2,3'-[3H]-naphth[2,1-b]-1,4-oxazine,(iv)1-isopropyl-3,3-dimethylspiropiperidine-2,3'-[3H]-naphth[2,1-b]-1,4-oxazine,(v)8'-bromo-1,3,3-trimethylspiropiperidine-2,3'-[3H]-naphth[2,1-b]-1,4-oxazine,(vi)5'-methoxy-1,3,3-trimethylspiropiperidine-2,3'-[3H]-naphth[2,1-b]-1,4-oxazine,(vii)9'-methoxy-1,3,3-trimethylspiropiperidine-2,3'-[3H]-naphth[2,1-b]-1,4-oxazine,(viii)1,2',3,3-tetramethylspiropiperidine-2,3'-[3H]-naphth[2,1-b]-1,4-oxazine,(ix)5'-methoxy-1,2',3,3-tetramethylspiropiperidine-2,3'-[3H]-naphth-[2,1-b]-1,4-oxazine,(x)2'-ethyl-1,3,3-trimethylspiropiperidine-2,3'-[3H]-naphth[2,1-b]-1,4-oxazine,and (xi)2'-ethyl-5'-methoxy-1,3,3-trimethylspiropiperidine-2,3'-[3H]-naphth[2,1-b]-1,4-oxazine.

The spiropiperidine-naphthoxazine compound of the present invention canbe prepared in the following manner. More specifically, aspiropiperidine-naphthoxazine compound represented by the generalformula (I) can be obtained by condensing a 1-nitroso-2-naphtholrepresented by the following general formula (IIa): ##STR3## wherein R₁₁through R₁₆ are as defined above in the formula (I), or an isomerthereof, that is, a keto-oxime compound, represented by the followinggeneral formula (IIb): ##STR4## wherein R₁₁ through R₁₆ are as definedabove in the formula (I), with an equimolar amount of atetrahydropyridinium salt represented by the following general formula(III): ##STR5## wherein R₁ through R₉ are as defined above in theformula (I), and X represents an anion such as an iodine anion, atosylate anion or a methyl sulfate anion, in the presence of a base in asolvent. This condensation reaction is accomplished by heating underreflux in the solvent, through which nitrogen gas is passed in thepresence of at least an equimolar amount of the base. If the reactionmixture is cooled after the condensation reaction, a brown crystal isprecipitated. The crystal is recovered by filtration and recrystallizedfrom an alcohol (such as methyl alcohol) to obtain aspiropiperidine-naphthoxazine compound represented by the generalformula (I).

As the reaction solvent, there can be mentioned polar solvents such asalcohols (for example, methyl alcohol, ethyl alcohol, isopropyl alcohol,n-propyl alcohol, and benzyl alcohol), methyl ethyl ketone, acetone,dimethyl-formamide, dimethylacetamide, and acetonitrile, and nonpolarsolvents such as benzene and toluene. As the base, there can bementioned inorganic bases such as potassium hydroxide and sodiumhydroxide, and organic bases such as triethylamine, pyridine,piperidine, and diethylamine.

The spiropiperidine-naphthoxazine compound of the present invention canbe dissolved in ordinary organic solvents such as benzene, toluene,chloroform, ethyl acetate, methyl ethyl ketone, acetone, ethyl alcohol,methyl alcohol, isopropyl alcohol, n-butyl alcohol, benzyl alcohol,tetrahydrofuran, dimethylformamide, dimethylsulfoxide, dioxane,acetonitrile, methylcellosolve, morpholine, and ethylene glycol, andeach of the obtained solutions is colorless in a dark place but shows ared violet color or blue violet color under irradiation with ultravioletrays. That is, each solution shows the photochromism phenomenon. Thephotochromic compound of the present invention can be dissolved in acolorless or transparent solution prepared from a transparenthomopolymer or copolymer or a blend thereof and an appropriate solvent,for example, a solution of a polymer as a host material described below,in at least one member selected from the abovementioned organicsolvents. As examples of the solution, there can be mentioned apolyvinyl acetate/acetone solution, a nitrocellulose/acetonitrilesolution, a polyvinyl chloride/methyl ethyl ketone solution, apoly(methyl methacrylate)/acetone solution, anacetylcellulose/dimethylformamide solution, a poly(vinylpyrrolidone)/acetonitrile solution, a polystyrene/benzene solution, andan ethylcellulose/methylene chloride solution.

When the above-mentioned photochromic solution or composition is coatedon a transparent support such as triacetylcellulose, polyethyleneterephthalate or baryta paper, and is then dried, a photochromicmaterial can be obtained which is colored red violet or blue violetunder irradiation with ultraviolet rays and is rendered colorless againif ultraviolet rays irradiation is stopped.

This photochromic material can be easily prepared according to a knownoptional method. More specifically, the compound represented by theformula (I) is dissolved in, kneaded with, or coated on a host materialsuch as a resin, an oil or fat, or a paper, whereby the compoundrepresented by the general formula (I) can be incorporated into a solidsuch as a film, a lens or a plate, an oil or fat, a liquid such as anemulsion or other material having an optional shape. The amount of thephotochromic compound of the present invention incorporated in amaterial as described above is not particularly critical, but thephotochromic compound is generally incorporated in an amount of 10⁻⁵ to20% by weight, and preferably, the photochromic compound is incorporatedin an amount of 10⁻⁴ to 10% by weight.

The present invention will now be described in detail with reference tothe following examples that by no means limit the scope of theinvention.

EXAMPLE 1

5.2 g of 1-nitroso-2-naphthol was added to 50 ml of absolute ethylalcohol through which nitrogen was passed, and the mixture was heatedunder reflux to completely dissolve 1-nitroso-2-naphthol. A solutioncomprising 4.2 ml of triethylamine, 8 g of1,2,3,3-tetramethyl-3,4,5,6-tetrahydropyridinium iodide and 25 ml ofabsolute ethyl alcohol was gradually added to the above solution over aperiod of 30 minutes and the mixture was refluxed for 2 hours.

The obtained reaction mixture was cooled and the precipitated browncrystal was recovered by filtration and recrystallized from methanolthree times to obtain 3.2 g of a light yellow needle crystal of intended1,3,3-trimethyl-spiropiperidine-2,3'-[3H]-naphth[2,1-b]-1,4-oxazine.

The physical properties of the obtained compound were as follows.

Melting point: 104° to 105° C.

    ______________________________________                                        Elementary analysis values (%):                                                           C         H      N                                                ______________________________________                                        theoretical values                                                                          77.52       7.53   9.51                                         found values  77.46       7.81   9.37                                         ______________________________________                                    

H¹ -NMR

The measurement was carried out by using TMS as the internal standard indeuterated dimethylsulfoxide as the solvent by means of a spectrometer,Model R-24B supplied by Hitachi Ltd. The obtained H¹ -NMR spectrum wasas shown in FIG. 1.

IR-Spectrum

The measurement was carried out by using an infrared spectrophotometer,Model JASCO A-3. The IR spectrum was as shown in FIG. 2.

Visible ray absorption spectrum

The visible ray absorption spectrum in a methyl alcohol solution beforeand after irradiation with ultraviolet rays was measured by using anultraviolet/visible spectrophotometer, Model 320 supplied by HitachiLtd. The concentration was 5×10⁻⁵ mole/l and the measurement temperaturewas 25° C. The obtained visible ray absorption spectrum was as shown inFIG. 3.

Decolorization speed

The decolorization speed and half-value period were determined from thechange with the lapse of time of the absorbency at the visibleabsorption maximum wavelength after irradiation with ultraviolet rays.The results obtained in various solvents are shown in Table 1. Theconcentration was 5×10⁻⁵ mole/l and the temperature was 25° C.

                  TABLE 1                                                         ______________________________________                                        Solvent      λmax (nm)                                                                          K (S.sup.-1)                                                                             t.sup.1/2  [S]                            ______________________________________                                        Methanol     560         6.15 × 10.sup.-2                                                                   11                                        Isopropyl alcohol                                                                          560         5.78 × 10.sup.-1                                                                   1.2                                       Benzyl alcohol                                                                             575         3.50 × 10.sup.-2                                                                   20                                        Dimethylsulfoxide                                                                          575         1.86 × 10.sup.-1                                                                   3.7                                       Toluene      580         1.16       0.6                                       ______________________________________                                    

Adaptability to repeated use

An XeCl exicimer laser, supplied by Lambda Physique, was used as theultraviolet ray irradiation source. The absorbency at a wavelength of560 nm just after irradiation was recorded by a storage oscilloscopesupplied by Sony Tectronics. The solvent was isopropyl alcohol, theconcentration was 5×10⁻⁵ mole/l, and the measurement temperature was 25°C. The results of the measurement of the relationship between theabsorbency just after irradiation with ultraviolet rays and thefrequency of repetition were as shown in FIG. 4-(a).

For comparison, the results of the measurement made on the compound(Comparative Example 1) of the following formula: ##STR6## and thecompound (Comparative Example 2) of the following formula: ##STR7## wereshown in FIGS. 4-(b) and 4-(c), respectively.

EXAMPLE 2

3.46 g of 1-nitroso-2-naphthol was added to 35 ml of absolute ethylalcohol through which nitrogen was passed, and the mixture was heatedand refluxed to completely dissolve the 1-nitroso-2-naphthol. A solutioncomprising 2.8 ml of triethylamine, 5.62 g of1-ethyl-2,3,3-trimethyl-3,4,5,6-tetrahydropyridinium iodide, and 20 mlof absolute ethyl alcohol was gradually added to the above solution overa period of 25 minutes, and the mixture was refluxed for 2 hours.

The obtained reaction mixture was cooled, and the precipitated browncrystal was recovered by filtration and recrystallized from methanolthree times to obtain 2.5 g of a light yellow needle crystal of intended1-ethyl-3,3-dimethylspiropiperidine-2,3'-[3H]-naphth[2,1-b]-1,4-oxazine.

The physical properties of the obtained compound were as follows.

Melting point: 102° to 103° C.

    ______________________________________                                        Elementary analysis values (%):                                                           C         H      N                                                ______________________________________                                        calculated value                                                                            77.89       7.84   9.08                                         found values  77.58       7.92   8.96                                         ______________________________________                                    

H¹ -NMR

The measurement was carried out in the same manner as described inExample 1.

δ(ppm): 0.8 (s, 3H), 1.2 (s, 3H), 0.9-1.3 (t, 3H), 2.2-2.6 (q, 2H),1.3-3.0 (b, 6H), 6.3-8.5 (m, 7H)

EXAMPLE 3

3.46 g of 1-nitroso-2-naphthol was added to 35 ml of absolute ethylalcohol through which nitrogen was passed and the mixture was heated andrefluxed to completely dissolve the 1-nitroso-2-naphthol. A solutioncomprising 2.8 ml of triethylamine, 6.45 g of1-n-propyl-2,3,3-trimethyl-3,4,5,6-tetrahydropyridinium iodide, and 20ml of absolute ethyl alcohol was gradually added to the above-solutionover a period of 25 minutes and the mixture was refluxed for 2 hours.

The obtained reaction mixture was cooled, and the precipitated browncrystal was recovered by filtration and recrystallized from methanolthree times to obtain 2.2 g of a light yellow needle crystal of intended1-n-propyl-3,3-dimethylspiropiperidine-2,3'-[3H]-naphth[2,1-b]-1,4-oxazine

The physical properties of the obtained compound were as follows.

Melting point: 101° to 102° C.

    ______________________________________                                        Elementary analysis values (%)                                                            C         H      N                                                ______________________________________                                        calculated values                                                                           78.22       8.13   8.69                                         found values  78.52       7.89   8.44                                         ______________________________________                                    

H¹ -NMR

δ(ppm): 0.8 (s, 3H), 1.2 (s, 3H), 0.7-1.1 (t, 3H), 1.1-1.7 (m, 2H),2.5-2.8 (t, 2H), 1.0-3.0 (b, 6H), 6.3-8.5 (m, 7H)

EXAMPLE 4

3.46 g of 1-nitroso-2-naphthol was added to 35 ml of absolute ethylalcohol through which nitrogen was passed, and the mixture was heatedand refluxed to completely dissolve the 1-nitro-2-naphthol. A solutioncomprising 2.8 ml of triethylamine, 5.90 g of1-isopropyl-2,3,3-trimethyl-3,4,5,6-tetrahydropyridinium iodide, and 20ml of absolute ethyl alcohol was gradually added to the above solutionover a period of 25 minutes, and the mixture was refluxed for 2 hours.

The obtained reaction mixture was cooled, and the precipitated browncrystal was recovered by filtration and recrystallized from methanolthree times to obtain 1.3 g of a light yellow needle crystal of intended1-isopropyl-3,3-dimethylspiropiperidine-2,3'-[3H]-naphth[2,1-b]-1,4-oxazine.

The physical properties of the obtained compound were as follows.

Melting point: 100° to 101° C.

    ______________________________________                                        Elementary analysis values (%):                                                           C         H      N                                                ______________________________________                                        calculated values                                                                           78.22       8.13   8.69                                         found values  77.97       8.11   8.89                                         ______________________________________                                    

H¹ -NMR

δ(ppm): 0.8 (s, 3H), 1.2 (s, 3H), 0.9-1.3 (d, 6H), 2.7-3.3 (m, 1S),1.0-3.0 (b, 6H), 6.3-8.5 (m, 7H)

EXAMPLE 5

5.04 g of 6-bromo-1-nitroso-2-naphthol was added to 35 ml of absoluteethyl alcohol through which nitrogen was passed, and the mixture washeated and refluxed to completely dissolve the6-bromo-1-nitroso-2-naphthol. A solution comprising 2.8 ml oftriethylamine, 5.34 g of1,2,3,3-tetramethyl-3,4,5,6-tetrahydropyridinium iodide and 20 ml ofabsolute ethyl alcohol was gradually added to the above solution over aperiod of 30 minutes, and the mixture was refluxed for 2 hours.

The obtained reaction mixture was cooled, and the precipitated browncrystal was recovered by filtration and recrystallized from methanolthree times to obtain 2.6 g of a light yellow needle crystal of intended8'-bromo-1,3,3-trimethylspiropiperidine-2,3'-[3H]-naphth[2,1-b]-1,4-oxazine.

The physical properties of the obtained compound were as follows.

Melting point: 108° to 109° C.

    ______________________________________                                        Elementary analysis values (%)                                                            C         H      N                                                ______________________________________                                        calculated values                                                                           61.13       5.67   7.50                                         found values  61.33       5.70   7.32                                         ______________________________________                                    

H¹ -NMR

δ(ppm): 0.8 (s, 3H), 1.2 (s, 3H), 2.1 (s, 3H), 1.0-3.0 (b, 6H), 6.3-8.5(m, 6H)

EXAMPLE 6

4.06 g of 3-methoxy-1-nitroso-2-naphthol was added to 35 ml of absoluteethyl alcohol through which nitrogen was passed and the mixture washeated and refluxed to completely dissolve the3-methoxy-1-nitroso-2-naphthol. A solution comprising 2.8 ml oftriethylamine, 5.34 g of1,2,3,3-tetramethyl-3,4,5,6-tetrahydropyridinium iodide, and 20 ml ofabsolute ethyl alcohol was gradually added to the above solution over aperiod of 25 minutes and the mixture was refluxed for 2 hours.

The obtained reaction mixture was cooled, and the precipitated browncrystal was recovered by filtration and recrystallized from methanolthree times to obtain 2.6 g of a light yellow needle crystal of intended5'-methoxy-1,3,3-trimethylspiropiperidine-2,3'-[3H]-naphth[2,1-b]-1,4-oxazine.

The physical properties of the obtained compound were as follows.

Melting point: 98° to 99° C.

    ______________________________________                                        Elementary analysis values (%)                                                            C         H      N                                                ______________________________________                                        calculated values                                                                           74.05       7.46   8.63                                         found values  73.54       7.12   8.41                                         ______________________________________                                    

H¹ -NMR

δ(ppm): 0.8 (s, 3H), 1.2 (s, 3H), 2.1 (s, 3H), 1.0-3.0 (b, 6H), 3.8 (s,3H), 6.3-8.5 (m, 6H)

EXAMPLE 7

4.06 g of 7-methoxy-1-nitroso-2-naphthol was added to 35 ml of absoluteethyl alcohol through which nitrogen was passed, and the mixture washeated and refluxed to completely dissolve the7-methoxy-1-nitroso-2-naphthol. A solution comprising 2.8 ml oftriethlamine, 5.34 g of 1,2,3,3-tetramethyl-3,4,5,6-tetrahydropyridiniumiodide, and 20 ml of absolute ethyl alcohol was gradually added to theabove solution over a period of 25 minutes, and the mixture was refluxedfor 2 hours.

The obtained reaction mixture was cooled, and the precipitated browncrystal was recovered by filtration and recrystallized from methanolthree times to obtain 1.9 g of a light yellow needle crystal of intended9'-methoxy-1,3,3-trimethylspiropiperidine-2,3'-[3H]-naphth[2,1-b]-1,4-oxazine.

The physical properties of the obtained compound were as follows.

Melting point: 105° to 106° C.

    ______________________________________                                        Elementary analysis values (%):                                                           C         H      N                                                ______________________________________                                        calculated values                                                                           74.05       7.46   8.63                                         found values  73.72       7.33   8.51                                         ______________________________________                                    

H¹ -NMR

δ(ppm): 0.8 (s, 3H), 1.2 (s, 3H), 2.1 (s, 3H), 1.0-3.0 (b, 6H), 4.0 (s,3H), 6.3-8.5 (m, 6H)

EXAMPLE 8

3.46 g of 1-nitroso-2-naphthol was added to 35 ml of absolute ethylalcohol through which nitrogen was passed, and the mixture was heatedand refluxed to completely dissolve the 1-nitroso-2-naphthol. A solutioncomprising 2.8 ml of triethylamine, 5.62 g of2-ethyl-1,3,3-trimethyl-3,4,5,6-tetrahydropyridinium iodide, and 20 mlof absolute ethyl alcohol was gradually added to the above solution overa period of 25 minutes and the mixture was refluxed for 2 hours.

The obtained reaction mixture was cooled, and the precipitated browncrystal was recovered by filtration and recrystallized from methanolthree times to obtain 0.5 g of a light yellow needle crystal of intended1,2',3,3-tetramethylspiropiperidine-2,3'-[3H]-naphth[2,1-b]-1,4-oxazine.

The physical properties of the obtained compound were as follows.

Melting point: 103° C.

    ______________________________________                                        Elementary analysis values (%):                                                           C         H      N                                                ______________________________________                                        calculated values                                                                           77.89       7.84   9.08                                         found values  77.56       7.79   8.82                                         ______________________________________                                    

H¹ -NMR

δ(ppm): 0.8 (s, 3H), 1.2 (s, 3H), 2.1 (s, 3H), 2.4 (s, 3H), 1.0-3.0 (b,6H), 6.3-8.5 (m, 7H)

EXAMPLE 9

4.06 g of 3-methoxy-1-nitroso-2-naphthol was added to 35 ml of absoluteethyl alcohol through which nitrogen was passed, and the mixture washeated to completely dissolve the 3-methoxy-1-nitroso-2-naphthol. Asolution comprising 2.8 ml of triethylamine, 5.62 g of2-ethyl-1,3,3-trimethyl-3,4,5,6-tetrahydropyridinium iodide, and 20 mlof absolute ethyl alcohol was gradually added to the above solution overa period of 25 minutes, and the mixture was refluxed for 2 hours.

The obtained reaction mixture was cooled, and the precipitated browncrystal was recovered by filtration and recrystallized from methanolthree times to obtain 0.7 g of a light yellow needle crystal of intended5'-methoxy-1,2',3,3-tetramethylspiropiperidine-2,3'-[3H]-naphth[2,1-b]-1,4-oxazine.

The physical properties of the obtained compound were as follows.

Melting point: 94° to 95° C.

    ______________________________________                                        Elementary analysis values (%):                                                           C         H      N                                                ______________________________________                                        calculated values                                                                           74.53       7.74   8.28                                         found values  74.21       7.53   8.02                                         ______________________________________                                    

H¹ -NMR

δ(ppm): 0.8 (s, 3H), 1.2 (s, 3H), 2.1 (s, 3H), 2.4 (s, 3H), 1.0-3.0 (b,6H), 3.8 (s, 3H), 6.3-8.5 (m, 6H)

EXAMPLE 10

3.46 g of 1-nitroso-2-naphthol was added to 35 ml of absolute ethylalcohol through which nitrogen was passed, and the mixture was heatedand refluxed to completely dissolve the 1-nitroso-2-naphtol. A solutioncomprising 2.8 ml of triethylamine, 5.90 g of2-n-propyl-1,3,3-trimethyl-3,4,5,6-tetrahydropyridinium iodide, and 20ml of absolute ethyl alcohol was gradually added to the above solutionover a period of 25 minutes, and the mixture was refluxed for 2 hours.

The obtained reaction mixture was cooled, and the precipitated browncrystal was recovered by filtration and recrystallized from methanolthree times to obtain 0.4 g of a light yellow needle crystal of intended2'-ethyl-1,3,3-trimethylspiropiperidine-2,3'-[3H]-naphth[2,1-b]-1,4-oxazine.

The physical properties of the obtained compound were as follows.

Melting point: 98° to 99° C.

    ______________________________________                                        Elementary analysis values (%)                                                            C         H      N                                                ______________________________________                                        calculated values                                                                           78.22       8.13   8.69                                         found values  77.98       7.86   8.39                                         ______________________________________                                    

H¹ -NMR

δ(ppm): 0.8 (s, 3H), 1.2 (s, 3H), 1.1-1.5 (m, 3H), 2.1 (s, 3H), 2.8-3.1(q, 2H), 1.0-3.0 (b, 6H) 6.3-8.5 (m, 7H)

EXAMPLE 11

4.06 g of 3-methoxy-1-nitroso-2-naphthol was added to 35 ml of absoluteethyl alcohol through which nitrogen was passed, and the mixture washeated and refluxed to completely dissolve the3-methoxy-1-nitroso-2-naphthol. A solution comprising 2.8 ml oftriethylamine, 5.90 g of2-n-propyl-1,3,3-trimethyl-3,4,5,6-tetrahydropyridinium iodide, and 20ml of absolute ethyl alcohol was gradually added to the above solutionover a period of 25 minutes, and the mixture was refluxed for 2 hours.

The obtained reaction mixture was cooled, and the precipitated browncrystal was recovered by filtration and recrystallized from methanolthree times to obtain 0.5 g of a light yellow needle crystal of intended2'-ethyl-5'-methoxy-1,3,3-trimethylspiropiperidine-2,3'-[3H]-naphth[2,1-b]-1,4-oxazine.

The physical properties of the obtained compound were as follows.

Melting point: 92° to 93° C.

    ______________________________________                                        Elementary analysis values (%):                                                           C         H      N                                                ______________________________________                                        calculated values                                                                           74.97       8.01   7.95                                         found values  74.65       7.95   7.54                                         ______________________________________                                    

H¹ -NMR

δ(ppm): 0.8 (s, 3H), 1.2 (s, 3H), 1.1-1.5 (m, 3H), 2.1 (s, 3H), 2.8-3.1(q, 2H), 3.8 (s, 3H), 6.3-8.5 (m, 6H)

CAPABILITY OF EXPLOITATION IN INDUSTRY

The spiropiperidine-naphthoxazine compound of the present invention is aphotochromic compound having an excellent adaptability to repeated use,and this compound can be preferably used for automatic lightquantity-adjusting plastic sun glasses, skiing goggles, sun visors,window panes, laminated glass sheets, packaging materials for foods,drinks and medicines, decorative articles, automobile trims, paints,inks, cosmetics such as manicures and lip sticks, and writable anderasable memory materials.

We claim:
 1. A spiropiperidine-napthoxazine compound represented by thefollowing general formula (I): ##STR8## wherein (a) R₁ represents alinear or branched alkyl group having 1 to 18 carbon atoms, an aralkylgroup having 7 to 15 carbon atoms, which may be substituted, an alkenylgroup having 1 to 10 carbon atoms or an aryl group having 6 to 15 carbonatoms, which may be substituted, (b) R₂, R₃, R₄, R₅, R₆, R₇, R₈, and R₉represent independently a group R₁ defined above, a hydrogen atom or analicyclic ring having 5 to 10 carbon atoms or a norbonyl or adamantylgroup, which norbonyl or adamantyl group is bonded between groupspresent on one skeleton carbon atom or between groups on adjacentskeleton carbon atoms (at the ortho-position), (c) R₁₀ represents ahydrogen atom, a linear or branched alkyl group having 1 to 18 carbonatoms, an aralkyl group having 7 to 15 carbon atoms, which may besubstituted, or an alkenyl group having 1 to 10 carbon atoms, and (d)R₁₁, R₁₂, R₁₃, R₁₄, R₁₅, and R₁₆ represent independently a hydrogenatom, a linear or branched alkyl group having 1 to 9 carbon atoms, analkoxyl group having 1 to 5 carbon atoms, a halogen atom, a nitro groupor a cyano group, said substituents present on the above recited groupswhich may be substituted being those substituents which do not adverselyaffect photochromic properties.
 2. A compound as set forth in claim 1,wherein in the general formula (I), (a) R₁ represents a linear orbranched alkyl group having 1 to 4 carbon atoms, (b) R₂, R₃, R₄, R₅, R₆,and R₇ represent independently a hydrogen atom, a methyl group or anethyl group, (c) R₈ and R₉ represent independently a methyl group or anethyl group, (d) R₁₀ represent a hydrogen atom or a linear or branchedalkyl group having 1 to 5 carbon atoms, and (e) R₁₁ through R₁₆represent independently a hydrogen atom, a halogen atom or an alkoxylgroup having 1 to 5 carbon atoms.